下列有关放射性药物不良反应的论述哪项不正确（）。

A.变态反应是最常见的放射性药物不良反应

B.放射性药物的不良反应主要由于放射性对机体的辐射损伤造成的

C.放射性药物不良反应的发生率低于X线检查常用的碘造影剂的不良反应发生率

D.放射性药物不良反应的发生率与药物种类有关

E.放射性药物不良反应大多数在药物注射后10余分钟至数小时发生

What on earth does happiness mean? I can’t give you its exact definition, but I’m sure if you love and help 16.        , you’ll get it.

I’ll never forget an old lady. She lives in 17.      small house alone. It is said that her husband and her son 18.    （die）in a road accident years ago. Her life is bitter, but she often helps others 19 .    a smile. Whenever it snows, she is always the first to clean the paths. She looks after several children living nearby. I am one of them. I often remember the stories she told us and her kind smile. Perhaps she is unlucky, but I think she is a happy person. Her life is full of 20.     （laugh）and love.

But I’m sad to see some people getting their happiness in bad ways. They talk 21.    （noisy）in cinemas and meeting rooms; they destroy trees to enjoy themselves and they laugh at others’ shortcomings. Perhaps they feel happy at that time, 22.       they will never get true happiness because they 23.      （lose）their personality already.

Now I know what happiness is. 24.     means kindness, love and unselfishness. Above all, I have come to understand that 25.      （bring）happiness to others is getting ourselves happiness.